Apparatus for vapor phase processing ophthalmic devices

ABSTRACT

This invention discloses apparatus for processing one or more of a Lens Precursor, a Lens Precursor Form and an ophthalmic Lens. The apparatus provides for vapor phase processing of the subject Lens Precursor, a Lens Precursor Form and an ophthalmic Lens.

FIELD OF USE

This invention describes apparatus relating to the fabrication ofophthalmic devices and, more specifically, in some embodiments,apparatus for vapor phase processing of one or more of: a Lens Precursoruseful for the formation of a customized ophthalmic lens, an ophthalmicLens Precursor Form and an ophthalmic Lens.

BACKGROUND OF THE INVENTION

Ophthalmic lenses are often made by cast molding, in which a monomermaterial is deposited in a cavity defined between optical surfaces ofopposing mold parts. Multi-part molds used to fashion hydrogels into auseful article, such as an ophthalmic lens, can include for example, afirst mold part with a convex portion that corresponds with a back curveof an ophthalmic lens and a second mold part with a concave portion thatcorresponds with a front curve of the ophthalmic lens. To prepare a lensusing such mold parts, an uncured hydrogel lens formulation is placedbetween a plastic disposable front curve mold part and a plasticdisposable back curve mold part.

The front curve mold part and the back curve mold part are typicallyformed via injection molding techniques wherein melted plastic is forcedinto highly machined steel tooling with at least one surface of opticalquality.

The front curve and back curve mold parts are brought together to shapethe lens according to desired lens parameters. The lens formulation wassubsequently cured, for example by exposure to heat and light, therebyforming a lens. Following cure, the mold parts are separated and thelens is removed from the mold parts.

Cast molding of ophthalmic lenses has been particularly successful forhigh volume runs of a limited number of lens sizes and powers. However,the nature of the injection molding processes and equipment make itdifficult to form custom lenses specific to a particular patient's eyeor a particular application. Consequently, other techniques have beenexplored, such as: lathing a lens button and stereo lithographytechniques. However, lathing requires a high modulus lens material istime consuming and limited in the scope of the surface available andstereo lithography has not yielded a lens suitable for human use.

In prior descriptions, methods and apparatus for forming customizedlenses via the use of voxel based lithographic techniques have beendescribed. An important aspect of these techniques is that a lens isproduced in a novel manner where one of two lens surfaces is formed in afree form fashion without cast molding, lathing or other tooling. A freeformed surface and base may include a free flowing fluent media includedin the free formed surface. This combination results in a devicesometimes referred to as a Lens Precursor. According to the presentinvention a Lens Precursor including a free surface and fluent media areexposed to processing steps prior to exposure to fixing radiation andhydration treatments typically utilized to convert a Lens Precursor intoan ophthalmic lens.

It is desirable therefore to utilize the accessibility to the free formsurface and media thereupon to treat the Lens Precursor in additionalmeans via treatment with chemical species in the gas phase around theprecursor surface. Additional methods may derive from similar treatmentof the free formed surface of an ophthalmic lens formed after exposing aLens Precursor to fixing methodology

SUMMARY OF THE INVENTION

The present invention is directed to the methods for treating ophthalmicLens Precursors in the vapor phase, wherein, in some embodiments, thetreated Lens Precursor can subsequently be utilized to form anophthalmic lens. Generally, according to the present invention, a LensPrecursor is formed via a polymerization process and either subsequentlyor coincidentally located in an apparatus that allows for the control ofa gaseous environment surrounding the formed Lens Precursor. Variousembodiments of the present invention control this gaseous environmentsurrounding the Lens Precursor to a vapor phase with differentconstituents, wherein, at least one of the constituents affects aphysical property of the Lens Precursor or a lens formed from the LensPrecursor.

Additional methods include vapor phase treatment performed upon a lensthat is disposed upon a mandrel or forming optic.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a depiction of a Lens Precursor within a vapor phasechamber.

FIG. 2 illustrates additionally exemplary processing environmentsdescribed that facilitate control of vapor phase processing of LensPrecursors and lenses.

FIG. 3 illustrates a vapor phase chamber apparatus with control valves.

FIG. 4 illustrates a vapor phase chamber and a controller.

FIG. 5 illustrates a vapor phase chamber including a thermal controldevice.

FIG. 6 illustrates a vapor phase chamber including a radiation source.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides for apparatus and methods of treating oneor both of a lens and a Lens Precursor with vapor phase processing. Inthe following sections detailed descriptions of embodiments of theinvention will be given. The description of both preferred andalternative embodiments though thorough are exemplary embodiments only,and it is understood that to those skilled in the art that variations,modifications and alterations may be apparent.

GLOSSARY

In this description and claims directed to the presented invention,various terms may be used for which the following definitions willapply:

“Actinic Radiation” as used herein, refers to radiation that is capableof initiating a chemical reaction, such as, for example, polymerizationof a Reactive Mixture.

“Arcuate” as used herein, refers to a curve or bend like a bow.

“Beer's Law” as referred to herein and sometimes referred to as“Beers-Lambert Law” is: I(x)/I0=exp (−αcx), wherein I(x) is theintensity as a function of distance x from the irradiated surface, I0 isthe incident intensity at the surface, α is the absorption coefficientof the absorbing component, and c is the concentration of the absorbingcomponent.“Collimate” as used herein means to limit the cone angle of radiation,such as light radiation that proceeds as output from an apparatusreceiving radiation as an input; in some embodiments the cone angle maybe limited such that proceeding light rays are parallel. Accordingly, a“collimator” includes an apparatus that performs this function and“collimated” describes the effect on radiation.“DMD” as used herein, a digital micromirror device is a bistable spatiallight modulator consisting of an array of movable micromirrorsfunctionally mounted over a CMOS SRAM. Each mirror is independentlycontrolled by loading data into the memory cell below the mirror tosteer reflected light, spatially mapping a pixel of video data to apixel on a display. The data electrostatically controls the mirror'stilt angle in a binary fashion, where the mirror states are either +Xdegrees (on) or −X degrees (off). For current devices, X can be either10 degrees or 12 degrees (nominal). Light reflected by the on mirrorsthen is passed through a projection lens and onto a screen. Light isreflected off to create a dark field, and defines the black-level floorfor the image. Images are created by gray-scale modulation between onand off levels at a rate fast enough to be integrated by the observer.The DMD (digital micromirror device) is sometimes DLP projectionsystems.“DMD Script” as used herein shall refer to a control protocol for aspatial light modulator and also to the control signals of any systemcomponent, such as, for example, a light source or filter wheel eitherof which may include a series of command sequences in time. Use of theacronym DMD is not meant to limit the use of this term to any oneparticular type or size of spatial light modulator.“Fixing Radiation” as used herein, refers to Actinic Radiationsufficient to one or more of: polymerize and crosslink, essentially allReactive Mixture comprising a Lens Precursor or lens.“Fluent Lens Reactive Media” as used herein means a Reactive Mixturethat is flowable in either its native form, reacted form, or partiallyreacted form and, a portion or all Reactive Media may be formed uponfurther processing into a part of an ophthalmic lens.“Free-form” as used herein “free-formed” or “free-form” refers to asurface that is formed by crosslinking of a Reactive Mixture and is notshaped according to a cast mold, lathe, or laser ablation.“Gel Point” as used herein shall refer to the point at which a gel orinsoluble fraction is first observed. Gel point is the extent ofconversion at which a liquid polymerization mixture becomes a solid.“Lens” as used herein “lens” refers to any ophthalmic device thatresides in or on the eye. These devices can provide optical correctionor may be cosmetic. For example, the term lens can refer to a contactlens, intraocular lens, overlay lens, ocular insert, optical insert orother similar device through which vision is corrected or modified, orthrough which eye physiology is cosmetically enhanced (e.g. iris color)without impeding vision. In some embodiments, the preferred lenses ofthe invention are soft contact lenses are made from silicone elastomersor hydrogels, which include but are not limited to silicone hydrogels,and fluorohydrogels.“Lens Precursor” as used herein, means a composite object consisting ofa Lens Precursor Form and a Fluent Lens Reactive Mixture in contact withthe Lens Precursor Form. For example, in some embodiments Fluent LensReactive Media is formed in the course of producing a Lens PrecursorForm within a volume of Reactive Mixture. Separating the Lens PrecursorForm and adhered Fluent Lens Reactive Media from a volume of ReactiveMixture used to produce the Lens Precursor Form can generate a LensPrecursor. Additionally, a Lens Precursor can be converted to adifferent entity by either the removal of significant amounts of FluentLens Reactive Mixture or the conversion of a significant amount ofFluent Lens Reactive Media into non-fluent, incorporated material.“Lens Precursor Form” as used herein, means a non-fluent object with atleast one optical quality surface which is consistent with beingincorporated, upon further processing, into an ophthalmic lens.“Lens Forming Mixture” as used herein, the term or “Reactive Mixture” or“RMM” (reactive monomer mixture) refers to a monomer or prepolymermaterial which can be crosslinked to form an ophthalmic lens. Variousembodiments can include lens forming mixtures with one or more additivessuch as: UV blockers, tints, photoinitiators or catalysts, and otheradditives one might desire in an ophthalmic lenses such as, contact orintraocular lenses.“Mold” as used herein, refers to a rigid or semi-rigid object that maybe used to form lenses from uncured formulations. Some preferred moldsinclude two mold parts forming a front curve mold part and a back curvemold part.“Radiation Absorbing Component” as used herein, the term “refers toradiation-absorbing component which can be combined in a reactivemonomer mix formulation and which can absorb radiation in a specificwavelength range.Reactive Mixture (also sometimes referred to herein as: Lens FormingMixture or Reactive Monomer Mixture and with same meaning as “LensForming Mixture”).“Release from a mold” as used herein, “release from a mold,” means thata lens becomes either completely separated from the mold, or is onlyloosely attached so that it can be removed with mild agitation or pushedoff with a swab.“Stereolithographic Lens Precursor” as used herein means a LensPrecursor where the Lens Precursor Form has been formed by use of astereolithographic technique.“Substrate” A physical entity upon which other entities are placed orformed.“Transient Lens Reactive Media” as used herein means a Reactive Mixturethat remains on a Lens Precursor Form and is not fully polymerized andmay remain in fluent or non-fluent form. Transient Lens Reactive Mediais significantly removed by one or more of: cleaning, solvating andhydration steps before it becomes incorporated into an ophthalmic lens.Therefore, for clarity, the combination of a Lens Precursor Form and thetransient lens Reactive Mixture does not constitute a Lens Precursor.“Voxel” as used herein “Voxel” or “Actinic Radiation Voxel” is a volumeelement, representing a value on a regular grid in three dimensionalspace. A Voxel can be viewed as a three dimensional pixel, however,wherein a pixel represents 2D image data a Voxel includes a thirddimension. In addition, wherein Voxels are frequently used in thevisualization and analysis of medical and scientific data, in thepresent invention, a Voxel is used to define the boundaries of an amountof actinic radiation reaching a particular volume of Reactive Mixture,thereby controlling the rate of crosslinking or polymerization of thatspecific volume of Reactive Mixture. By way of example, Voxels areconsidered in the present invention as existing in a single layerconformal to a 2-D mold surface wherein the Actinic Radiation may bedirected normal to the 2-D surface and in a common axial dimension ofeach Voxel. As an example, specific volume of Reactive Mixture may becrosslinked or polymerized according to 768×768 Voxels.“Voxel-based Lens Precursor” as used herein “Voxel-based Lens Precursor”means a Lens Precursor where the Lens Precursor Form has been formed byuse of a Voxel-based lithographic technique.“Xgel” as used herein, Xgel is the extent of chemical conversion of acrosslinkable Reactive Mixture at which the gel fraction becomes greaterthan zero.“Mandrel” as used herein, includes an article with a shaped surface forsecuring an ophthalmic lens.Methods

The inventive art herein concerns treating one or both of an ophthalmiclens and an ophthalmic Lens Precursor with vapor phase processing.Generally, one or both of the ophthalmic Lens Precursor and theophthalmic lens are formed via a voxel lithographic based technique.

Referring to FIG. 1, a generic form of a Lens Precursor 100 isillustrated. A Lens Precursor Form 140 with a first and second generallyarcuate surface and the first generally arcuate surface 150 defined bythe surface of a mandrel 145 upon which the base is formed. A secondgenerally arcuate surface 130 formed via a voxel lithographic technique.The Lens Precursor Form 140 may be comprised of polymers formed as thepolymers passed their Gel Point, wherein the lens form has not yet beenexposed to fixing radiation.

In some embodiments, Gel Point can be determined using soxhletequipment. A polymer reaction can be stopped at different time pointsand a resulting polymer is analyzed to determine a weight fraction ofresidual insoluble polymer. Resulting data can be extrapolated to apoint where no gel is present. This point where no gel is present is theGel Point.

In other embodiments, a gel point may also be determined by analyzing aviscosity of a reaction mixture during a reaction. The viscosity can bemeasured, for example, using a parallel plate rheometer, with reactionmixture between the plates. At least one plate should be transparent toradiation at the wavelength used for polymerization. The point at whichthe viscosity approaches infinity is the gel point. Gel point may occurat a same degree of conversion for a given polymer system and specifiedreaction conditions.

Continuing with FIG. 1, this type of Lens Precursor 100 includes aninternal boundary 130 between the form 140, wherein a gel point has beenreached, and fluent media 110, wherein the gel point has not beenreached.

Processing of the Lens Precursor Form 140 and fluent media 110 maygenerate an optical quality surface 120. Processing may include forexample exposure of the Lens Precursor Form 140 to actinic radiation.Numerous polymer systems may be used to form entity 100 in a voxellithographic manner, and still further it may be apparent that othertechniques may define a Lens Precursor 100 which includes a LensPrecursor Form 140 upon which a fluent media 110 is deployed.

The exemplary voxel lithographic Lens Precursor 100 is a combination ofdifferent regions 110, 120, 130, 140, as described above. Each of theseregions 110, 120, 130, 140, may include a combination of differentchemical moieties. For example, each region may include one or more of:polymeric entities, multimeric entities, monomer, solvent and desolvedchemicals to mention a few.

A Lens Precursor 100 has not been subjected to fixing radiation,therefore, in some embodiments, significant levels of interdiffusion ofvarious materials will occur. Some of the various materials will accessthe surface 120 and, which may in some embodiments be in physicalcontact with a vapor phase 170 beyond the surface 120 is boundary.

The present invention addresses method and apparatus to controlinteraction between the vapor phase 170 and the surface of the LensPrecursor 120.

In some embodiments of the present invention, a vapor phase 170proximate to a precursor surface 120 is controlled via an enclosure 160around the Lens Precursor 100. Some embodiments may also includeenclosing a substrate 145 supporting a Lens Precursor.

Referring now to FIG. 2, a Lens Precursor 201 is illustrated which isformed by voxel lithographic processing techniques. The Lens Precursor201 is located upon an arcuate optical forming surface 212. A Volume ofReactive monomer mixture in which the Lens Precursor was formed has beendrained from the enclosure.

Following draining, an environment proximate to the Lens Precursorincludes a vapor phase 203. In some embodiments, the vapor phase 203 iscontained by walls, 201-208 included in the processing apparatus 200.Flow 204-206 of a liquid or gas through vapor phase 203 may be used tointroduce desired attributes into the vapor phase. The apparatus mayhave interfacing fixtures including an inlet 209 and an outlet 210, thatallow an external controlling environment to establish vapor flow or insome embodiments establish a static vapor phase condition, oralternatively evacuate the vapor phase 203 in part or essentiallyentirely.

In some embodiments, mechanical fixtures allow evacuation of vaporphases. In some particular embodiments, a tube 211 or any other deviceproviding fluid communication between an interior of the chamber 203 andan exterior of the chamber 206 may define an exit port for evacuation.For example, in some embodiments different flow patterns 204-206 may beestablished through the use of evacuation tubes 211, wherein tubes 211may be located in different manners and locations within the apparatusand essentially allow for removal of some or all of a vapor phase 203from an area proximate to the lens precursor 201 and specificallyremoval of some or all of a vapor phase 203 from an atmosphere proximateto a surface 202 exposed to the vapor phase 203.

In some embodiments, tube 211 location or the location of another deviceproviding fluid communication, allows for a flow of vapor phase 203 tobe directed proximate to the lens surface 202. Other embodiments includea Lens Precursor 201 with an apex generally orthogonal to agravitational direction, and a tube with an opening for vacating one orboth of: a gas and a liquid, below a plane of the apex, such the one orboth of the gas and liquid are down past the Lens Precursor.

Numerous controlling features may allow control of a Vapor Phaseinteraction with a Lens or Lens Precursor 201 in an environment.Features may include, by way of non-limiting example, one or more of:shaped tubes 211, gas injectors, gas distributors, valves, mass flowcontrollers, pressure regulators, vacuum systems, gas mixing systems andother such apparatus not illustrated.

For example, in some embodiments, treatment of a Lens Precursor 201 mayinvolve flowing gas into and out of an area defined by containmentbarriers 207-208 via an inlet 209 and an outlet 210. Some specificembodiments may include flow of an inert gas including one or more of:Argon and Nitrogen. The flow of gas can be controlled, for example, by amass flow controller to regulate a specific quantity of a gas includedin the vapor phase 203 to pass over the Lens Precursor 201. In someembodiments, such an inert gas flow 204-206 may be used to facilitatelimiting exposure of a lens precursor 201 to particular gasses otherwisepresent in a typical ambient. In other embodiments, an inert gas flow204-206 allows the desiccating of the Lens Precursor 201 fromconstituents that have an appreciable vapor pressure and outgas from theLens Precursor 201 in such an environment. As a non limiting example,solvent present in a Reactive Monomer Mixture used to form the LensPrecursor 201 may be removed from the Lens Precursor 201 into the vaporphase 203 and exited through outlet 210.

Still further embodiments of flowing an inert ambient may relate todesiccating or removal by outgassing of materials that are present fromthe environment of the Lens Precursor 201 as opposed to one or more ofthe Lens Form and fluent Lens Reactive Media itself. It may be clear toone skilled in the arts that there could be a variety of processingoptions that would derive by flowing an inert gas through an apparatuscapable of isolating the Lens Precursor environment.

Other embodiments may include the introduction of a liquid through aninlet 204, wherein the liquid interacts with the vapor phase 203 andthereby imparts characteristics into the vapor phase 203 that are usefulfor treating the surface 202 of the lens precursor 201.

Additional and related embodiments include a mandrel 212 supporting anentity that has already been exposed to fixing irradiation and thereforeconstitutes a Lens rather than a Lens Precursor 201. In still furtherembodiments, a lens formed by exposing said voxel lithographic LensPrecursor 201 to fixing radiation may subsequently be converted to aLens Precursor 201 by the addition of fluent Lens Reactive Media to asurface of the Lens. Again, the environment of such a Lens Precursor 201may include processing embodiments where the Lens Precursor 201 isprocessed with an inert vapor phase 203. It may be apparent to oneskilled in the arts that a broad array of similar embodiments may derivefrom processing numerous types of Lens Precursors 201 including, withoutlimitation, Lens Precursors 201 where a Lens Form is made using stereolithographic techniques, lathing techniques, or cast molding techniques.

Referring now to FIG. 3, in some alternative embodiments, an apparatus300 that processes one or more of: a Lens Precursors, Lens PrecursorForm and a Lens, includes valves 311-312 connected to an inlet port 310and an outlet port 320. In some exemplary embodiments, an inlet portvalve 310 and outlet port valve 320 are capable of being closed toeffectively isolate atmosphere within a chamber 314 wherein the chamber314 contains a Lens Precursor 315 formed via voxel by voxelpolymerization or a mandrel 313 or other substrate.

In some embodiments, the apparatus maintains a static ambient atmosphereor Vapor Phase 314 above the Lens Precursor 315. In other controlled,varied atmospheres, it may be apparent to one skilled in the arts, thatsuch an isolation may limit the amount of a particular species presentin the vapor ambient to comprise only that present when the apparatuswas set into an isolating state.

Further embodiments may derive from processing a Lens Precursor 315 in asimilar manner where the ambient is isolated by the apparatus tomaintain a static vapor phase over the Lens Precursor 315. In thisembodiment type, the Lens Precursor 315 itself may contain species thatare volatile and outgas from the Lens Precursor 315 into the staticvapor phase. In some embodiments this material may be present in thefluent lens reactive media itself and it may diffuse through the topsurface 120 and into the vapor phase. Volatile species may initially befound in a lens form and diffuse into the fluent lens reactive media. Insome cases the outgassing process may add a constituent into the ambientvapor phase 314 that reaches a vapor pressure of the constituent andthereafter maintains an equilibrium concentration above the LensPrecursor 315 surface. In different embodiments, the outgassing may notreach such an equilibrium condition and may increase the constituent'spartial pressure in the vapor phase over time.

A static vapor phase over a Lens Precursor 315 may also result inembodiments, where a vapor phase 311 becomes enriched in chemicalmoieties that are resulting byproducts of chemical reactions that occurin the parts of the Lens Precursor 315 itself. In alternativeembodiments of this type, the reactions that generate the byproducts maythemselves be activated by action upon the Lens Precursor 315 while itis in the environment of the vapor phase processing apparatus 300.Without limitation, in some embodiments this externally activated typeof process may be activated for example by one or both of thermalprocessing of the Lens Precursor 315, by light activated processing byradiation other than light.

Embodiments may also include a liquid or gas introduced into the chamber314 via the controllable valve 311-312. Various embodiments may includeintroduction of an inert gas, wherein other embodiments includeintroduction of a gas including a catalyst for a reaction on or withinthe Lens Precursor 315. In some particular embodiments, a monomer may beintroduced via the valve, wherein the monomer may be equivalent to amonomer used to form the Lens Precursor 315 or a different monomer whichmay be controllably polymerized, such as for example, via a voxel byvoxel polymerization, to enhance the Lens Precursor 315.

Referring now to FIG. 4, still further embodiments of static phase vaporprocessing may derive when the isolated environment may include a liquidphase of a chemical constituent. A liquid phase constituent 409 mayinclude, for example, a monomeric form from the reactive monomermixture, or alternatively a solvent present in the reactive monomermixture. Various embodiments may derive by including a liquid phaseconstituent 409 into an environment wherein the vapor phase 413 isisolated and becomes populated by gaseous forms of the molecules thatcomprise the liquid phase 409.

Embodiments may also include reaction apparatus 400 with an inlet valve410 introducing a gas 412 via an outlet 411 into a liquid phaseconstituent 409. In some embodiments (as illustrated), the outlet 411provides liquid communication between an area exterior to the chamber415 and an area interior to the chamber 413. Additionally, it may beadvantageous to position a location of the outlet relative to the one ormore of: Lens Precursor 401, Lens Precursor Form and Lens. For example,in some embodiments (as illustrated) the outlet 411 may be located at apoint below an apex of the Lens Precursor 401. Other embodiments mayinclude an inlet 411A that is above an apex of the Lens Precursor 401.

As the gas 412 passes over, bubbles through, or otherwise interacts witha liquid phase constituent 409, the gas may extract gaseous forms ofmolecules that comprise the liquid phase constituent 409 and bring themolecules into the vapor phase environment 413 proximate to the LensPrecursor 401. Variables which may affect such embodiments may includeone or more of: varying a rate of flow of gas, varying a type of gas,temperature of gas, combinations of gas, order of introduction of gas.

In various embodiments, vapor phase chemicals may interact with one orboth of a Lens Precursor and Lens Precursor Form. Details of suchinteractions may create different embodiments in their own right.

In a first example, constituents in a vapor phase are capable of one orboth of physisorbing or chemisorbing upon the surface of the LensPrecursor 401. A constituent is adsorbed, or otherwise interacts with aLens Precursor surface; it may react with that surface and result in achemically modified surface region.

In some embodiments, adsorbed material may not react initially butrather may diffuse within the fluent Lens Reactive Media and possiblyinto the Lens Form as well. When this vapor phase constituent thusadsorbs and diffuses into the bulk, subsequent processing may be enactedto change a characteristic of the Lens Precursor or Lens Form the vaporphase constituent is adsorbed into.

In some embodiments, a Vapor Phase constituent 409 includes a ReactiveMonomer which interacts with a surface of a Lens Precursor 401 or Lens.Subsequent processing by fixing radiation, polymerizes the ReactiveMonomer present on the surface of a Lens Form, Lens Precursor 401 orLens and result in a change of the physical or chemical properties ofthe a Lens, Lens Precursor 401 or Lens Form. An abundant variety ofchemical compounds and mixtures may be utilized thereby enabling a largevariety of embodiments within the scope of this invention.

Another way this art of exposing the Lens Precursor 401 to materialwhich adsorbs or chemisorbs to modify the Lens Precursor 401 is based onwhether a chemical compound or chemical mixture which is exposed in thevapor phase to the Lens Precursor 401 is already a constituent of theLens Precursor 401. In some embodiments, a vapor phase constituent mayinclude a monomer already present in a Reactive Mixture such as anEtafilcon A reactive monomer mixture. The Etafilcon A can be used toform a Lens Precursor 401 using a voxel based lithographic process. Theincorporation of Etafilcon A monomer into the Lens Precursor 401 mayresult in a different level of this monomer at different positions inthe Lens Precursor 401.

Alternatively, another embodiment type results when a vapor phasechemical that is a new chemical species to the Lens Precursor 401 isexposed to a Lens Precursor 401. The new chemical species may directlycause, act as a catalyst, or otherwise facilitate change in propertiesof various locations within the Lens Precursor 401.

Still further embodiments include a Lens Precursor 401 exposed to avapor phase constituent which is also a constituent of the LensPrecursor 401. If a vapor phase is made to be controllably static in theenvironment of the Lens Precursor 401, then volatile species found inthe Lens Precursor 401 may desorb from the Lens Precursor into the vaporphase. As the desorption occurs the partial pressure of the desorbingspecies will increase until or unless it is at the point whereequilibrium occurs between the vapor and the surface of the LensPrecursor 401. In some embodiments therefore, the static environmentwhere equilibrium has been reached may allow the concentrations withinthe Lens Precursor of a volatile species to come to equilibrium. Sincethe physical and chemical properties, for example ability to behydrated, are a function of the compositional makeup of both lenses andLens Precursors 401, this static vapor phase treatment protocol mayresult in defined properties of a lens made in this manner.

In some alternative embodiments the vapor phase constituents may reactupon interaction with a particular portion of a Lens Precursor 401 orlens. In some embodiments, the vapor phase constituent may react uponthe top surface of the Lens Precursor 401, fluent reactive media. Inother embodiments, the constituent may first diffuse into the fluentlens reactive media before reacting or alternatively through the fluentmedia and into the lens form before reacting. It may be apparent to oneskilled in the art that each of these embodiment types could result indifferent physical and or chemical properties of a lens formulated withthese vapor phase processing innovations.

In another aspect of the present invention, in some embodiments, asensor, such as for example, a sensor generating an analog or digitalsignal based upon a condition within the chamber 413, may be locatedwithin or proximate to the chamber 413 and generate a signal based upona condition within the chamber 413. A logical controller, such as, forexample a computer server, a workstation, a microprocessor,micro-controller or other device able to execute logical instructionsmay be in logical communication with one or more of the sensor 416, thevalves 410,414 or other controllable feature. The logical controller mayreceive data, issue command and store data useful to operation of theapparatus.

Referring now to FIG. 5, in addition to the vapor phase processingenvironment and the diverse embodiments that have been describedrelating to vapor phase processing, it can be supplemented by additionof ability to heat a Lens Precursor environment. A thermal energycontrol device 502, for example a heat source or a chilling device, isplaced proximate to a vapor phase treatment apparatus 500 may be used toincrease thermal energy in one or both of a Lens Precursor 501 and avapor phase environment. Alternative manners of heating the environmentmay include heating the vapor phase itself that is being fed into thetreatment apparatus. In fact, there may be numerous manners of treatingthe lens or Lens Precursor 501 environment with external thermalprocessing.

A thermal control device 502 which includes a heating apparatus mayinclude one or more of a resistance coil, a heat exchange unit and athermo electric Peltier device. Thermal processing may be useful fornumerous changes to the nature of the Lens Precursor or lens. By way ofa non-limiting example, volatile components within one or more of thelens, lens form or fluent lens reactive media may be made more volatileby heating of an environment in which one or more of a Lens Form, LensPrecursor 501 and Lens are present. In some embodiments therefore, it ispossible to effectively remove volatile components from the variousLens, Lens Precursors and Lens Precursor Forms via the application ofheat.

Thermal processing may also be utilized to enact reaction processes tooccur at a higher rate. In another non limiting example, cross linkingmay be accelerated by the presence of thermal heating. Vapor phase maybe used to transport a monomeric compound into a Lens, Lens Precursor501 or Lens Form and by thermal treatment it may be made to react withinthe Lens, Lens Precursor 501 or Lens Form.

Still further embodiments include a thermal energy control device 502which includes a cooling device, such as for example, a chiller, athermoelectric cooler, chilled water supply, or other apparatus capableof decreasing an amount of thermal energy available within a vapor phaseenvironment and thereby decreases the amount of thermal energy availableto one or more of a Lens Precursor Form, Lens Precursor 501, andophthalmic Lens. Decreased thermal energy may be used to slow somechemical reactions manifested in the one or more of a Lens PrecursorForm, Lens Precursor 501, and ophthalmic Lens.

Referring now to FIG. 6, in another aspect of the present invention,apparatus for providing vapor phase processing 600 may also include aradiation source capable of emanating light radiation forphotoprocessing one or more of: a Lens Precursor 601; a Lens PrecursorForm and a Lens. In some embodiments, photoprocessing is controlled viaa same voxel lithographic processing light system that was used to forma Lens Precursor 601, Lens Precursor Form, Lens or other lens object.

In some embodiments, a light source 602 may control exposure of aphotoreactive chemical on the surface 603 of one or more of: a LensPrecursor 601, Lens Precursor Form, Lens or other lens object. Theexposed photoreactive chemical may physisorb onto the surface 603 whereit they may interact with photon exposure and in so interact bechemically modified and incorporated onto the surface. Numerous types orphoto based reactions may be included in embodiments within the scope ofthis invention and without loss of generality may include regionaltreatment of the Lens Precursor 601 or lens object by voxel lithographictreatment, masked lithography treatment or more generally unmaskedphoton exposure to the entire Lens Precursor 601 or lens object.

It may be apparent that the numerous examples of methods of treating alens object or a Lens Precursor 601 in an environment where the vaporphase surrounding is controlled with an apparatus have been described inrelatively simple single processing steps or combinations of steps.However, it should also be clear that these various processing steps mayas well be combined into more sophisticated treatment processes. In anon limiting sense these combinations may be combinations of processingtechniques that occur in a sequential manner. Alternatively, a number ofprocessing techniques may be activated in a parallel mode.

As a result of the processing embodiments that have been described inrelation to this inventive art, there are numerous changes that may becaused to occur in both Lens Precursors 601 and lens objects that areproduced. These resulting products may themselves define new deviceembodiments of the voxel lithographic technique. Without limitation thenature of changes to the lens objects and Lens Precursors 601 mayinclude chemical changes to the surface and bulk material properties ofthe Lens Precursor or the lens object. In other device embodiments,vapor phase treatment may result in changes to material stress aspects,the density of portions of the lens object and Lens Precursors 601 andfrom a more global perspective the shape that these devices will assumein their final form. Still other devices may derive from changes to thesurface composition of the lens objects and Lens Precursors which mayresult in changes to the wettability of the surface. Further devicediversity may result from changes in color, incorporation of dies orchanges of absorbance of regions of the Lens Precursor 601 or lensobject. Other changes that may be processed into the lens objects andLens Precursors 601 may also include changes to the permeability of thebulk materials that make up the devices. In other embodiments of thealtered devices changes through vapor phase processing may includealteration of the thermal stability of the devices. The processingtechniques also may enable lens objects that contain chemicals orpharmaceutical compounds to be incorporated through vapor phaseprocessing. It may be apparent to one skilled in the art, that thesedevice embodiments are mentioned as examples of what may be possible andare not meant to limit the diversity of altered devices that may derivefrom vapor phase processing of Lens Precursors 601 and lens objects.

The invention claimed is:
 1. An apparatus for processing a LensPrecursor, the apparatus comprising: a mandrel with an arcuate surfacefor supporting said Lens Precursor; a chamber enclosing a vapor phaseenvironment proximate to the Lens Precursor and at least a portion ofthe arcuate surface of the mandrel, wherein said vapor phase environmentaffects at least one physical property of the Lens Precursor duringprocessing; an inlet for admitting one or both of a gas and a liquidinto said chamber; and a registration feature for aligning the apparatuswith an external device, wherein said external device comprises adigital mirror device as a source of voxel by voxel radiation, andwherein the processing of the Lens Precursor is done in a Free Formmanner on a voxel by voxel basis within said chamber.